1. Technical Field
The present disclosure herein relates to a semiconductor device and a method for manufacturing the same, and more particularly, to a nitride-based semiconductor device and a method for manufacturing the same.
2. Background Information
A nitride of a group 3 element, i.e., GaN-based compound semiconductor has a wide bandgap in comparison with a typical Si or compound semiconductor. A nitride semiconductor, which is a direct-transition-type semiconductor, enables control of wavelengths of light from visible rays to ultraviolet rays. Furthermore, compared to typical compound semiconductors, a nitride semiconductor has excellent properties such as high thermal/chemical stability, high electron mobility, high saturated electron velocity, and large energy bandgap. Due to such properties, nitride semiconductors are widely applied to the fields in which the use of typical compound semiconductors is limited. For example, nitride semiconductors are applied to optical devices such as light-emitting diodes (LEDs) and laser diodes (LDs) and electronic devices for use in next-generation wireless communication or satellite communication systems required to have high power and high frequency characteristics.
In general, semiconductor devices are manufactured on expensive single-crystal growth substrates. Such growth substrates may include a single-crystal wafer which may be used to form a structure support and a compete lattice for epitaxial growth of a semiconductor layer such as an active layer. In the case of a nitride semiconductor device, since there is no lattice-constant-matched substrate, a sapphire substrate is commonly used, but a low thermal conductivity of this substrate causes degradation of the performance of a device. Therefore, researches are being carried out with respect to transporting a device to a host substrate having desirable optical characteristics, mechanical characteristics, or thermal characteristics. In particular, in the case of removing a sapphire substrate, since a device should be separated from a single-crystal substrate, expensive processing equipment such as laser lift-off (LLO) equipment is required, or the yield is degraded due to the complexity of a substrate separating process.